U.S. should fix aging infrastructure before building new

America's bridges, once a symbol of the nation's engineering and construction prowess, are crumbling.

Every day, millions of Americans drive over thousands of bridges that the government says are in lousy shape. In recent years, two have already collapsed, causing deaths, slowing transport and harming local businesses.

But instead of spending money to repair those bridges, many local politicians have pushed to use scarce funds to build new structures. Political expedience is taking precedence over common sense, and drivers and businesses are suffering.

"It's a lot harder to cut a ribbon on a pothole repair project," said Roger Millar, a vice president at Smart Growth America, an advocacy group that focuses on sustainable development.

Despite the recent infusion of $26 billion in federal "stimulus" spending, the problem is expected to worsen as tens of thousands of bridges built nearly 50 years ago for the national Interstate highway system reach the end of their useful life. Just to keep the system from further falling apart would require another $14 billion in federal spending per year, according to a recent CBO report. Needed improvements would cost another $50 billion, the CBO said.

But even without additional spending, the Highway Trust Fund is expected to go broke by 2015, in part because the federal 18.4-cent a gallon gasoline tax hasn't been raised in 20 years. Gasoline taxes make up about 92 percent of federal highway funding and about 40 percent of state funding. But state gas tax rates vary widely – from just eight cents a gallon in Alaska to 50.6 cents in New York.

Even as the federal gas tax has remained flat, revenues have been shrinking because overall gasoline consumption has been falling since 2007. As the average mileage of the cars and trucks on the road continues to rise, those gas tax receipts will continue to fall.

To cover projected federal highway spending, CBO estimates the gas tax would have to be raised by 10 cents a gallon. That's not a campaign promise likely to win support from many voters.

Since 2008, Congress has kept the trust fund afloat by tapping $41 billion in other taxes; another $12.6 billion has been authorized for 2014. Given the ongoing federal budget squeeze, those transfers aren't sustainable, CBO said.

State funding for bridge repair and replacement is also coming up short.

Since the Great Recession shrank income and property taxes, states have been scrambling to balance the books at a time when few voters are in the mood for tax increases. That's left many transportation departments fending off efforts to tap their revenues to fund a variety of non-transportation needs.

"Instead of trying to raise the taxes they're just trying to protect the money that's already there," said Rall.